Dislocation density based crystal plasticity finite element simulation of Al bicrystal with grain boundary effects

2014 ◽  
Vol 1651 ◽  
Author(s):  
Zhe Leng ◽  
David P. Field ◽  
Alankar Alankar
Keyword(s):  
Finite Element ◽  
Dislocation Density ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Crystal Plasticity ◽  
Microstructure Evolution ◽  
Polycrystalline Materials ◽  
Boundary Character ◽  
Crystal Plasticity Finite Element ◽  
Grain Boundary Character

ABSTRACTCrystal plasticity finite element method is a useful tool to investigate the anisotropic mechanical behaviors as well as the microstructure evolution of metallic materials and it is widely used on single crystals and polycrystalline materials. However, grain boundary involved mechanisms are barely included in the polycrystalline models, and modeling the interaction between the dislocation and the grain boundaries in polycrystalline materials in a physically consisstent way is still a long-standing, unsolved problem. In our analysis, a dislocation density based crystal plasticity finite element model is proposed, and the interaction between the dislocation density and the grain boundaries is included in the model kinematically. The model is then applied to Al bicrystals under 10% compression to investigate the effects of grain boundary character, e.g. grain boundary misorientation and grain boundary normal, on the stress state and the microstructure evolution. The modeling results suggest a reasonable correspondence with the experimental result and the grain boundary character plays a crucial role in the stress concentration and dislocation patterning.

SEM-ECP Analysis of Grain-Boundary Character Distribution in Polycrystalline Materials

1996 ◽  
Vol 54 ◽  
pp. 354-355
Author(s):  
Tadao Watanabe
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Migration ◽  
Polycrystalline Materials ◽  
Grain Boundary Character Distribution ◽  
Boundary Character ◽  
Grain Boundary Character ◽  
Character Distribution ◽  
Boundary Character Distribution

As demonstrated early 1980’s (1), the scanning electron rnicrocopy-electron channelling pattern (SEM-ECP) technique is very powerful in determination of orientation of individual grains and the character of grain boundaries in polycrystalline materials. Figure 1(a) and (b) show SEM and ECP images of a grain boundary in polycrystal line iron-6.5 mass % silicon ribbon produced by rapid solidification and subsequent annealing. We can intuitively recognize from the SEM-ECP image that the character of the boundary is of <100> tilt type with about 7° misorientation angle. This kind of direct observation is very useful for a study of grain boundary migration and grain growth.This paper discusses advantages of the SEM-ECP technique for the precise determination of the character of grain boundary and for statistical analysis of grain boundaries to bridge roles of individual grain boundaries and bulk properties in a polycrystal. The new microstructural parameter associated with grin boundary termed “grain boundary character distribution (GBCD)” which was introduced by the present author (2,3) and has been utilized in designing and engineering grain boundaries in order to produce desirable and/or high bulk performance in polycrystalline materials (4,5). GBCD describes the type and the frequency of different types of grain boundaries, ie. random general boundaries and special boundaries like low-angle boundaries and low Σ coincidence boundaries.

scholarly journals Influence of Grain Boundary Character and Annealing Time on Segregation in Commercially Pure Nickel

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Shery L. Welsh ◽  
Monica Kapoor ◽  
Olivia D. Underwood ◽  
Richard L. Martens ◽  
Gregory B. Thompson ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Annealing Time ◽  
Electron Backscatter Diffraction ◽  
Atom Probe ◽  
Pure Nickel ◽  
Polycrystalline Materials ◽  
Boundary Character ◽  
Grain Boundary Character ◽  
Commercially Pure

Commercially pure nickel (Ni) was thermomechanically processed to promote an increase in Σ3 special grain boundaries. Engineering the character and chemistry of Σ3 grain boundaries in polycrystalline materials can help in improving physical, chemical, and mechanical properties leading to improved performance. Type-specific grain boundaries (special and random) were characterized using electron backscatter diffraction and the segregation behavior of elements such as Si, Al, C, O, P, Cr, Mg, Mn, B, and Fe, at the atomic level, was studied as a function of grain boundary character using atom probe tomography. These results showed that the random grain boundaries were enriched with impurities to include metal oxides, while Σ3 special grain boundaries showed little to no impurities at the grain boundaries. In addition, the influence of annealing time on the concentration of segregants on random grain boundaries was analyzed and showed clear evidence of increased concentration of segregants as annealing time was increased.

Metal precipitation at grain boundaries in silicon: Dependence on grain boundary character and dislocation decoration

2006 ◽  
Vol 89 (4) ◽  
pp. 042102 ◽  
Author(s):  
T. Buonassisi ◽  
A. A. Istratov ◽  
M. D. Pickett ◽  
M. A. Marcus ◽  
T. F. Ciszek ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Character ◽  
Grain Boundary Character ◽  
Metal Precipitation

Coupled Simulation of the Static Recrystallization in Hot Deformed Austenite on Mesoscale

2007 ◽  
Vol 558-559 ◽  
pp. 1213-1218
Author(s):  
Cheng Wu Zheng ◽  
Na Min Xiao ◽  
Dian Zhong Li ◽  
Yi Yi Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Crystal Plasticity ◽  
Microstructure Evolution ◽  
Static Recrystallization ◽  
Element Model ◽  
Stored Energy ◽  
Coupled Simulation ◽  
Crystal Plasticity Finite Element ◽  
Stored Energy Of Deformation

The kinetics and microstructure evolution during static recrystallization (SRX) of hot-deformed austenite in a low carbon steel are simulated by coupling a cellular automaton (CA) model with a crystal plasticity finite element model (CPFEM). The initial deformed characteristics, which include the stored energy of deformation and the crystallographic orientation induced by a plane strain hot compression are simulated using a crystal plasticity finite element model. These data are mapped onto the CA regular lattices as the initial parameters for SRX simulation. The coupled simulation results reveal that the heterogeneous distribution of the stored energy of deformation results in non-uniform nucleation and a slower kinetics. The influence of non-uniform distribution in stored energy on the SRX kinetics and microstructure evolution is discussed based on a microstructural path (MP) analysis.

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